Paul Ryan just came out with positive support for it. I think DeMint did too.
Paul Ryan ‘loves’ Herman Cain’s 9-9-9 tax plan
At the end of this article is this "update":
Update: Kevin Seifert, a spokesman for Ryan, clarified late Thursday that the budget committee chairman was not endorsing Cain or the specifics of the 9-9-9 plan, but rather that he loved that it was becoming “a starting point for a larger conversation on tax reform.”